The present invention relates to a manufacturing method of composite material, especially to a manufacturing method of a ladder-like phosphorus-containing polysilsesquioxanes organic/inorganic nanocomposite material.
Due to requirements for higher performance, improvement of various properties of the polymer materials such as thermal resistance, flame retardance, and mechanical feature is getting more important. A lot of research for improving polymer properties has been done continuingly. During theses characters, the most important is flame retardance because that the disadvantage of polymer is inflammable. When there is a fire, the polymer is easy to burn and generate toxic haze as well as char that lead to serious damage and properties loss.
Thus it is an important issue to develop flame retardant and related technology for polymers. Flame retardant is divided into two groups: organic and inorganic. The organic flame retardant mainly consists of halogen and phosphide. However, virulent toxin and corrosive gas such as hydrochloric acid, HBr, HCN and dioxin are released while burning halogen. This not only damage our health but also cause degradation of ozone layer on the earth so as to generate an enormous hole and cause damages to ecology of the earth. Due to more strict regulations and environmental protection consciousness, it is prohibited to use halogens. Thus there is a trend to develop new generation of new flame retardant.
Organic/inorganic hybrid material not only combines advantages of organic/inorganic fields but also possesses it's unique feature. In the related researches, organic polyorganosiloxanes is one of the important points. The basic structure of organic polyorganosiloxanes includes silicon, oxygen and siloxanes with organic group attached on the silicon. In 1863, Friedel and Crafts prepared the first compounds, in which carbon and silicon atoms were directly united. The first practical synthesis of organosilanes was accomplished by F. Stanley Kipping in 1904 by Grignard reagent reacting with silicon tetrachloride for the formation of the Si—C bond. Then by hydrolysis reaction and condensation reaction of siloxanes, silsesquioxanes are obtained. Until 1960, J. F. Brown, L. H. Vogt have established a synthesis method of silsesquioxanes.
As to the present invention, the sol-gel technology is used to prepare organic/inorganic hybrid material containing phosphorus and silicon so as to increase flame retardance of the material. Due to special features of sol-gel reaction, organic/inorganic materials are compatible, without phase separation. Inorganic materials are distributed inside organic materials in nano-scale so as to form nanocomposites materials with different properties of two materials.